The purpose of this project is to examine the metabolism of amino acids, particulary proline, by anaerobic organisms found in dental plaque. An organism isolated from saliva, which requires proline as an essential nutrient has been investigated inpure culture. Results, so far, suggest that the metabolism of this organism may involve the utilization of "Stickand reactions" involving both amino acids and lactic acid as substrates for the reduction of proline. Preliminary characterization suggests the organism is a member of the Peptostreptococci. The work is being directed forward the characterization of the kinetics and mechanisms of these reactions and their effects on dental plaque biochemistry.